I have seen this and my solution was to comment the lot out...
I am not sure it is even necessary, since when installing packages with info files (after removing those lines, of course) I see a line in the console saying something to the effect that the info files are being regenerated (or similar). That is with installpkg and upgradepkg, I cannot say if this works with gslapt/slapt-get too.
BTW, I have made quite a few changes to the sbbuilder templates, so if anyone wants to try them out, I will attach them here. They go in /usr/share/sbb/template. I compressed them all, since they are very small, but I have not modified all of them.
One thing I added was handling for cases when the source tarball or the top-level directory within it have non-standard names, different from what the package name should be.
I also modified requiredbuilder to fix the dependency mess created by deps like:
pixman >= 0.19.2-i586-1vl60
when it should only be:
pixman >= 0.19.2
This way, deps are met as long as you have the same or higher version number installed, regardless of whether it is a VL or Slackware package.